substrate, daft question

[steve borthwick]

probably the daftest question you will hear (you decide!) but when people talk about potting soil as a suitable substrate for most T's, would a simply "growbag" be ok?

[Szandra Speier]

I think it's ok.

[Tim Gibbons]

Just ensure there are no harmful additives. I prefer coir myself as tried potting soil/spider sub and find the Phorid Flies love it because it contains more organic matter. Coir also retains moisture a lot better, especially if keeping species that need higher humidity.

[Peter Roach]

probably the daftest question you will hear (you decide!) but when people talk about potting soil as a suitable substrate for most T's, would a simply "growbag" be ok?

There have been many daft questions asked over the years but this isnt one of them.

I sometimes use coir but these days generally use a mix of top soil, general purpose compost, seed compost and/or a mix of all 3 or 4 of them depending on what i have at that particular moment. Tarantulas are fairly versatile and can adapt to many types of substrate so dont worry too much.
At the moment I have just started experimenting with organic, peat free compost (early days yet) but i like the look and 'feel' of it, now I just have to see if the T's like it as well as me

I have never used a 'growbag' as a source for substrate but I would be slightly wary as there definitely will be some sort of additives, what types I have no idea.
A bag of top soil is usually around £2.50 and a small bag of general purpose compost approx £3-4 (?) both of which will last a long time.
Top soil used by itself will usually dry out quickly, so I use this for species that prefer their substrate on the drier side like Brachypelma, Aphonopelma and Grammostola.

I generally use a mixture of any of these.